Rotary valve.



Patented May 2|, l90l. C. H. PARSHALL.

ROTARY VALVE.

ication filed Jan. 5, 1901.)-

2 Shaets$heet l.

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v INVENTOR M/ZM ATTORNEYS No. 674,684. Patented May 21, IQOI. c. H. PABSHALL. ROTARY VALVE.

(Application filed Jan 5, 1901.)

2 Sheets-Sheet 2.

(No Model.)

WITNESSES:

ATTO NEYS m: nunms PETERS to, PNDTO-LIYNO.. wnumomm a. a

NITED STATES ATENT Orrics.

CHARLES H. PARSHALL, OF NEWV YORK, N. Y., ASSIGNOR TO JOHN KEENAN, OF SAME PLACE.

ROTARY VALVE.

SPECIFICATION forming part of Letters Patent No. 674,684, dated May 21, 1901.

Application filed January 5,1901. Serial No. 42.209. (No model.)

To all 1072,0111, it may concern:

Be it known that 1, CHARLES HENRY PAR- SHALL, a citizen of the United States, residing at New York, borough of Manhattan, and State of New York, havein vented certain new and useful Improvements in Rotary Valves, of which the following is a specification.

This invention relates to valves for the expander of refrigerating apparatus such as shown and described in my copending application, Serial No. 740,868, filed December 19, 1895); and the object of the same is to provide a valve with a peculiar means of adjustment for compensating for the expansion and contraction of its casing.

My invention consists, further, of certain features of construction and combinations of parts to be hereinafter described and then particularly claimed.

In the accompanying drawings, Figure 1 is anenlarged detail perspective view of the expander, illustrating the valve-gear which may be employed. Fig. 2 is a transverse section through the slide and guide of the valvegear. Fig. 3 is a detail perspective view of the crank, arm, and pivoted dog of the cutoflt valve. Fig. 4 is a longitudinal central section of the expander. Fig. 5 is a perspective View of the upper set of valves of the expander and their casing. Fig. 6 is a section on the line 6 6 of Fig. 5 through the valve on the off side of the upper part of the expanding-cylinder; and Fig. 7 is a section on line 7 7, Fig. 6.

The expander A is provided at its upper and lower ends, respectively, with valve-casings F G, the open-ended cylindrical shell of the expander being provided with a centrally-located cylindrical partition to, which forms the expanding-chamber a. Arranged at one side of the expanding-chamber a, are two airchests a a which are separated from each other by means of a web or partition of, while on the opposite side of the expanding-chamber there are two similar air-chests 0, d which are separated from each other by a horizontal web or partition a the chests a a at one side being separated from the chests a a at the opposite side by means of vertical partitions a (Indicated in dotted lines in Fig. 4..) The valve-casing F consists of two cylindrical valve-chambers f f respectively, separated by a central web or partition f*. The valve-chamber f is provided with two ports 1 f communicating with the air-chest a and expanding-chamber a, respectively, while the valve-chain ber f is provided with two ports f' f, communicating with the expanding-chamber a and the air-chest a respectively.

The valve-casing G at the lower part of the expander consists of two cylindrical valvechambers g g, respectively, separated by a central web or partition g The valve-chainber g is provided with two ports g 9 comin unicating with the air-chest a and expanding-chamber ct, respectively, while the valve-chamber g is provided with two ports 9 g, communicating with the expandingchamber a and air-chest a, respectively.

Contained in each of the valve-chambers f f g g is a valve H H H H respectively, of the same size and shape as the valve-chamber and each arranged to close its respective port communicating with the expandingchamber. The radius of the face of each valve corresponds with the radius of the valvechamber, so that when the face of the valve is against the seat surrounding the port it can eltectively shut off all communication betweenthe valve-chamber and the expandingcharnber. The valve H is opposed to the port f forming the communication from the airchesta to the expanding-chamber a.

1} represents the inlet, by means of which the air is admitted to the air-chest a As the air while in said air-chest a. is of a practically normal temperature, there will be no material contraction or expansion of the easing of the valve-chamber f. The valve H therefore snugly fits the valve-chamberf, and as the pressure of the air from the air-chest a to the expandingchamber at normally presses the valve toward its seat at f and as the air fromthe air-chest a does not cause any material expansion or contraction of the casing of the valve-chamber f it is not necessary to provide the valve with any adjustment device, such as hereinafter described. The valve H, which is arranged within the valve-chamber f and is substantially cylindrical in shape, has its sides cut away at f and the top of the valve cut away at f", so that the top of the valve will have slightly less size than the valve-chamber in order that the valve H can be adjusted to compensate for the expansion and contraction of the easing of the valve-chamber f, as hereinafter set forth.

Referring more particularly to Figs. 6 and 7, the shaft K of the valve H is provided at .one end with a stuffing-box 7c, projecting through the valve-casing into the valve-chamber f. The inner face of the stuffingbox It is grooved vertically at k to provide a vertical guide, in which is contained a movable block 71: The end of the valve-chamber f opposite the stufling-box 7c is provided with a vertical guide 103, opposed to the guide and contained in the guide 70 is a movable block 70 Journaled in blocks k k is the shaft K of the valve H. One end of the shaft K projects through and beyond the outer face of the stuffing-box It, so that it may be properly connected with the valve-gear hereinafter described. Projecting through the top of the casing of the valve H are two set-screws k which are screwed into correspondinglythreaded bores or holes arranged vertically above the center of the shaft K, one setscrew being opposed to each movable block. Formed in the top of each of the movable blocks 10 k is a recess 70, in each of which recesses there is arranged a spring 70 bearing against the bottom of its respective recess and the inner end of the set-screw. The purpose of the springs 10 is to normally hold the valve H against its valve-seat, formed around the port), which communicates with the expansion-chambera, and the purpose of the set-screw 70 is to regulate the pressure of the said springs. The bore of the stuffing-box k is slightly greater in diameter than the diameter of the shaft K in order that the said shaft can have a limited movement to allow of its vertical adjustment by the drical in shape, and, like the valve H, has

one of its sides cut away to form a port or recess to register with the port of its respective valve-chamber communicating with the expanding-chamber. The valves H H may also be provided with adjusting devices similar to those of the valves H H but it is not necessary, however, to provide the said valves with this adjusting device, as theaction of the air on these valves continuously presses them against their respective valve-seats f g while in the case of the valves H H the air is continuously forcing them from their seats. The ofiports of the valves H H Valves H H correspond, respeccould not be used as seats against which the said valves may work, inasmuch as there is a tendency for ice to form at the said sides of the valves, and consequently there would not be an easy action and a proper lit. The piston J of the expanding-chamber a is provided with a piston-rod J, which is guided through the usual stuiiing-box in the valvecasing G at the lower part of the expander and has the well-known pitman-and-crank connection with the drive-shaft.

The air is admitted into the expander throughthe inlet '5, which leads directly into the ai r-chest a and by means of the portsf f from the air-chest a to the expanding-chainber a at a point above the piston J, where it is expanded by the action of the downward stroke of the piston and then exhausted through the portsf f into the air-ohest a", the valve H controlling the passage of the air from the air-chest a into the expanding-chamber a, and the valve H controlling the passage of the air from the expanding-chamber a to the air-chest a The motions of the valves H H are so timed and the valves are so arranged in relation to each other that when the valve H is moved to uncover the ports f f from the air-chest a to the expanding-chamber 0; the valve H is moved to cover the ports from the expanding-chamber a to the air-chest a in order that the downward reciprocating action of the piston will properly expand the air in the expanding-chamber. The valve H uncovers its ports for admitting air into the expanding-chamber a during the first quarter of the downward stroke of the piston and then immediately closes the port, the other valve H remaining closed also. Thus the air in the expanding-chamberis expanded to at least four times its own volume by the single downward stroke of the piston J. When the piston makes a stroke in the opposite direction, or upward, the valve H is moved by its properly-timed valve-gear to uncover the port f and establish a communication from the expanding-chamber a into the air-chest a and when the piston has completed its stroke the said valve is moved to cover the port and closes the communication between the expanding-chamber and air-chest a the valve H being simultaneously moved to uncover the port from the air-chest a? into the expanding-chamber a, so that the described action may be repeated and the air repeatedly expanded within the expanding-chamber. The expanded air is led from the airchest a to the air-chest a by means of the inclined communicating pipe Z (indicated in dotted lines in Fig. 4) and is admitted, by means of the port controlled by the valve H from the ai r-chest ctinto the expanding-chamber a at a point below the piston J, where it is again expanded by the reciprocating action of the piston and afterward exhausted from the expanding-chamber a through the port controlled by the valve H into the air-chest IIO a, from whence it passes through the outlet 1" into the pipe D to perform its refrigerating action in the ice-box D.

In order to cause the valves to properly coaet, so as to control the admission and exhaust of the air, it is necessary to provide them with a suitable valve-motion, such as shown in my said copending application and which may be constructed as follows: Referring to Fig. 1, m is a connecting-rod leading from a suitable power device to the valves. On the shaft K of the valve H is fixed a bell-crank lever N, one arm n of which is connected to the eccentric-rod m by means of a link m so that by means of the eccentric-rod m the bell-crank lever N and the valve H can be rocked to open or close the port leading from the expanding-chamber a. 0 0 indicate, respectively, slideways fixed to the expanding-cylinder above and below the valve-casings F G, and P represents a sliding block arranged so as to be longitudinally reciprocated along the slideway 0. (See Fig. 2 for detail.) The top of the block P is provided with a recess 19, adapted to receive an ad j ustable tooth p, having an inclined face 19 and a stem 10 passing through and projecting below the lower edge of the block P. P represents a plate con nected to the lower edge of the block P by means of set-screws P and by means of which the plate can be vertically adjusted to or away from the bottom of the sliding block P. The lower end of the stem p of the tooth p rests upon the plate P, and by means of said plate and the stem 19 the tooth p can be adjusted vertically. The other end n of the bell-crank lever N is connected with one end of a link of, while the other end of the link is connected to the s'liding block P, the consequence of this connection being that during the operation of the valve H the bellcrank leverN causes the reciprocating movement of the sliding block P. From Fig. 3 it will be more clearly seen that shaft K of the valve H projects suitably beyond its stuffingbox, so as to overhang the slide-block P, said shaft K carrying at its projecting end a resisting-lug q, the upper end of which is bifurcated and is provided around the shaft K with a sleeve q. .Said sleeve is rigidly secured to the shaft K and is preferably so arranged as that the lug q is located vertically above the adjustable tooth p. Pivotally hung, by means of its hub r, on the valveshaft K is a dog 7', said hub of the dog being held between the forked part of the sleeve q of the resisting-lug q and arranged toswing on the valve-spindle K away from the resisting-lug (1 upon the movement of the slideblock P in the direction of the arrow, Fig. 1. During the movement of the slide-block P in the opposite direction indicated the adjustable tooth p engages the pivoted dog 1" and carries the same along with it, the dog during its forward movement coming in contact with the resisting-lug q, and thereby causing the rotation of the valve-shaft K and the valve I-I. During the return movement of the sliding block P in the direction of the arrow the inclined face 19 of the adjustable tooth p engages the pivoted dog and swings it away from the resisting-lug q, and as soon as the tooth p clears the dog the dog gravitates into normal hanging position, so that it may be moved against the resisting-lug upon the reverse movement of the slide-block P. The shaft K of the valve H is provided with a crank-arm S, to which is connected a rod S, which terminates in a dash-pot S as shown clearly in Fig. 1.

The action of the valve-gear described in connection with that of the valves H and H is the following: The rod m link m and arm it move the bell-crank lever upwardly, turning the valve H so as to close the port from the expanding-chamber a to the air-chest a This movement of the bell-crank lever causes the arm n to draw the link if and sliding block P toward the valve H, which movement causes the adjustable tooth p to engage the pivoted dog 1' and turn the valve l-I so as to open the port from the air-chest a into the expanding-chamber 0;. As soon as the adjustable tooth has cleared the pivoted dog 7' the valve H is immediately turned to close the port from the air-chest a to the expanding-chamber a by the drawing action of the dash-pot S The air admitted to the expanding-chamber r1, from the air-chest 0, 18, as before stated, now out off by the valve H during the piston-stroke at a point where the best results may be obtained. When the piston J has reached the end of its downward stroke, the valve H is moved to uncover its port from the expanding-chamber-into the air-chest a which remains uncovered during the entire upward stroke of the piston, the air at this part of the operation being expand ed to four times its original volume. The air after being exhausted from the expanding-chamber into the air-chest a is exhausted from the latter into the air-chest a, the valve H of which air-chest is operated similarly to that of the valve H. The air is exhausted from the air-chest of into the expandingchamber at below the reciprocating piston J during its upward stroke, where it is again expanded, and is then exhausted at the downward stroke of j the piston into the air-chest (1, the valve H of which has an adjusting device constructed similarly to that of the valve H and is provided with a bell-crank lever T, similar to the bell-crank lever N, said lever T being pivotally connected with the connecting-rod m and link m A valve-motion similar to the valve-m otion between the bell-crank lever N and the valve-shaft K is arranged between the bell-crank lever T and the valveshaft K of the valve H and the detailed description of the other suffices for the latter valve-motion. The slide-block for the lower valve-motion reciprocates on the guide 0, before referred to. The valves are so arranged in relation to each other that when the valve IOO . evaesa.

H is opened the valve H is closed and when the valve H is opened the valve H is closed, and vice versa. The shaft K of the valve H carries a crank-arm T, to which is connected a connectin g-rod T that terminates in adashpot T Thus it will be seen that the upper and lower sets of valves have substantially the same valve-gear.

The valves described are very reliable and practical in action and are especially adapted for an expander for refrigerating apparatus of the type shown.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. The combination, with the valve-casing, the valve-shaft journaled in the valve-casing, and the valve carried by the valve-shaft, of guides suitably formed in the ends of the valve-chamber, and bearingblocks mounted in said guides and in which said valve-shaft hears, substantially as set forth.

2. The combination, with the valve-casing, the valve-shaft journaled in the ends of the casing, and the valve carried by the valveshaft, of guides in the ends of the valve-chainber, bearing-blocks mounted movably in said guides and through which the valve-shaft extends, and means for adjusting the bearingblocks, substantially as -set forth.

3. The combination, with the valve-casing, and the valve carried by the valve-shaft, of guides in the ends of the valve-chamber, bearing-blocks in which the shaft turns, said blocks being arranged in said guides, and setscrews opposed to the bearing-blocks, so as to vary the pressure of the valve on its seat, substantially as set forth.

4. The combination, with the valve-casing, the valveshaft journaled in the casing, and the valve mounted on the valve shaft, of guides at the end of the valve-chamber, bearing-blocks guided by said guides and through which the shaft extends, said bearing-blocks being provided with recesses, springs contained in the recesses, and set-screws engaging said springs, substantially as set forth.

5. The combination, with the valve-casing, the valve-shaft, and the valve mounted thereon, of a stufiing-box for one end of the valvechamber, said stuffing-box having a bore of larger diameter than the valve-shaft, which passes therethrough, guides formed in the inner end of the stuffing-box and the opposite end of the valve-chamber, bearing-blocks contained in said guides and through which the valve-shaft extends, said hearing-blocks being provided with recesses, set-screws passing through the casing of the va1vechamber opposite to the bearing-blocks, and springs confined in said recesses by the set-screws, whereby the pressure of the valve on its seat'may -be varied, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed myname in presence of two subscribing witnesses.

CHARLES H. PARSHALL.

Witnesses:

PAUL GOEPEL, GEO. L. WHEELOCK. 

